Bug fix: typo in ident variable name

[fulghum]

Description

The HeartbeatLogEvent::dump method had a typo in the ident var name (indent was used instead). This caused a crash when dumping out heartbeat events.

Type of Change

• Bug fix
• New feature
• Documentation update
• Other (please specify below)

Checklist

• I have read and understood the CONTRIBUTING.md document.
• I have checked there aren't any other open Pull Requests for the desired changes.
• This PR resolves an issue #[Issue Number Here].

Tests

• All tests have passed.
• New tests have been added to cover the changes. (describe below if applicable).

Additional Information

I tested this change manually, but haven't added tests yet. Feel free to suggest a good spot for this test and I'll be happy to take another pass.

[julien-duponchelle]

Good catch !